American Carla Stefaniak had been vacationing with her sister-in-law in Costa Rica.

SAN JOSE, Costa Rica — The body of a 36-year-old South Florida woman killed while vacationing in Costa Rica showed signs of a violent death, according to her father.

“It was a death that was absolutely violent,” said Carlos Caicedo, the father of Carla Stefaniak, a US citizen who went missing late last month while staying at an apartment outside the Costa Rican capital of San Jose.

“And we ask ourselves why,” Caicedo said in an interview with CNN en Español. “We have no explanation.”

A Nicaraguan national, Bismarck Espinoza Martinez, 32, has been taken into custody in connection to Stefaniak’s death, according to Costa Rican officials. He was a security guard at the apartment complex where Stefaniak’s Airbnb was located.

On Monday, a partially decomposed body was found about 300 yards from the apartment complex, according to Walter Espinoza, a spokesman for Costa Rica’s Judicial Investigation Department.

An autopsy showed multiple stab wounds to the “neck and upper extremities,” as well as blunt force trauma to the head, Espinoza said.

There were also stains inside the apartment where she stayed “which are compatible with blood and which will be submitted to further investigation and comparison,” he said.

Victim was celebrating her birthday

Stefaniak’s sister-in-law, April Burton, said they went to Costa Rica to celebrate Stefaniak’s 36th birthday. They’d traveled together for six days, staying in beach towns outside San Jose, before Stefaniak dropped Burton off at the airport on November 27 and returned their rental car.

But her relatives grew concerned last week when she stopped contacting them and was not on her flight home from Costa Rica.

Up until that point, “I had constant communication with her,” Caicedo said. “She would send videos, texts.”

During their travels, Stefaniak told her father, “This is a safe country, and we feel really safe.”

Caicedo said he would remember his daughter as a happy and enthusiastic person who was always smiling, he said.

“She had no enemies, none,” he said, adding it took him a long time to find a picture of his daughter where she wasn’t smiling because “that was the type of woman she was.”

A friend of Stefaniak’s in New York was the last known person to have contact with her, Caicedo told CNN en Español. Stefaniak told her friend she was very thirsty and wanted to leave her Airbnb to get water, but it was raining too hard outside.

Suspect was staying in next apartment, per officials

Espinoza Martinez had been staying in the apartment next to Stefaniak’s rental, said Espinoza, the government spokesman.

“The person linked to this homicide (Espinoza Martinez) was close to her and had the time and place to commit the crime,” he said.

Detectives who interviewed people who had contact with Espinoza Martinez grew suspicious when they noticed his statements were contradictory, Espinoza said.

The security guard told Stefaniak’s relatives he last saw her around 5 a.m. on November 28, getting into an Uber to go to the airport, according to Leandro Fernandez, a friend of the victim.

But that didn’t make sense, Fernandez told WSVN, because Stefaniak’s flight out wasn’t until midday.

The family later learned there were no records in Stefaniak’s Uber account from that day, Fernandez said.